<template>
  <div>
    <h2>当前求和：{{sum}}</h2>
    <select v-model.number="n">
      <option value="1">1</option>
      <option value="2">2</option>
      <option value="3">3</option>
    </select>
    <button @click="increment">+</button>
    <button @click="decrement">-</button>
    <button @click="incrementOdd">当前求和为奇数再加</button>
    <button @click="incrementWait">等{{time}}ms再加</button>
  </div>
</template>

<script>
export default {
  name:'Count',
  data () {
    return {
      n:1,
      sum:0,
      time:500,
    }
  },
  methods: {
    increment(){
      this.sum+=this.n
    },
    decrement(){
      this.sum-=this.n
    },
    incrementOdd(){
      if(this.sum%2){
        this.sum+=this.n
      }
    },
    incrementWait(){
      setTimeout(()=>{
        this.sum+=this.n
      },this.time)
    },
  }
}
</script>
